Clotrimazole microemulsion and microemulsion-based gel: evaluation of buccal drug delivery and irritancy using chick chorioallantoic membrane as the model

ObjectivesTo investigate the efficacy of clotrimazole microemulsion (CTZ-ME) and its gel form, clotrimazole microemulsion-based gel (CTZ-MBG), for the treatment of oral candidiasis. MethodsCTZ-ME and CTZ-MBG were characterized for droplet size and texture, respectively. The ex-vivo permeation study and irritancy assessment of CTZ-ME and CTZ-MBG were performed using chick chorioallantoic membrane (CAM) as the model. Antifungal activity against Candida albicans ATCC 10231 of CTZ-ME and CTZ-MBG was determined by agar diffusion method compared to the blank counterparts. Key findingsCTZ-ME contained nano-sized droplets and CTZ-MBG had acceptable firmness and spreadability. CTZ-ME exhibited faster CAM permeation of the drug and larger inhibition zone than CTZ-MBG as the increased viscosity of CTZ-MBG resulted in more retardation and higher fluctuations in drug diffusion. As there were no detectable visual changes in CAM blood vessels after applying CTZ-ME or CTZ-MBG, both formulations were non-irritants. ConclusionsCTZ-ME and CTZ-MBG could deliver the drug through CAM, the model for buccal delivery. Additionally, they did not cause irritancy and had effective antifungal activity against C.albicans. The results indicated that CTZ-ME and CTZ-MBG were potential effective antifungal formulations to treat oral candidiasis.